TITLE:   GCN CIRCULAR
NUMBER:  33700
SUBJECT: GRB 230428A: Fermi GBM Final Real-time Localization
DATE:    23/04/28 09:19:35 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 09:08:58 UT on 28 Apr 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230428A (trigger 704365743.150826 / 230428381).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 121.8, Dec = -86.1 (J2000 degrees, equivalent to J2000 08h 07m, -86d 05'), with a statistical uncertainty of 15.9 degrees.

The angle from the Fermi LAT boresight is 30.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230428381/quicklook/glg_skymap_all_bn230428381.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230428381/quicklook/glg_healpix_all_bn230428381.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230428381/quicklook/glg_lc_medres34_bn230428381.gif